Ossicular prostheses are commonly placed in patients with ossicular destruction or disruption due to cholesteatoma, chronic otitis media, or congenital ossicular malformation. Osseointegration refers to a direct structural and functional connection between ordered, living bone and the surface of a load-carrying implant. Currently, an implant is considered as osseointegrated when there is no progressive relative movement between the implant and the bone with which it has direct contact.
Surgical insertion of an implant is commonly performed to replace one or both of the middle and innermost middle ear ossicles (i.e. incus and stapes, respectively) following surgical removal of these structures. A stapedectomy is a procedure for surgical removal of the stapes of the ear. It is known to use ossicular and stapes replacement prostheses to replace one or more of the ear ossicles. It is known to use a crimping attachment method to adhere to middle ear bones; however, this method can be inconsistent and lead to complications during recovery.
Methods of adjusting the length of ossicular implants include cutting an indexed rod that is pulled through a tympanic membrane plate, hereinafter referred to as TM plate, of the implant or cutting a flexible shaft attached to the TM plate. These methods are external adjustment methods and such methods require an increased surface area on the shaft of the implant. This extra surface area may potentially be snagged on tissue and lead to complications during implantation and recovery. Additionally, when shortened, the indexed length adjustment may leave material that must be removed from the end of the TM plate. The clipping of this section can leave a rough surface, which is undesirable for an implant that will be placed into tissue.
Current mechanisms for deformable prostheses are only capable of being manipulated to a deformed angle a single time, after which the angle cannot be readjusted. Additionally, it is known to provide prostheses which are provided with preset angles; however, providing present angles can be limiting as they are not infinitely adjustable on a patient-specific basis and, therefore, the closest angle must be chosen for a procedure even if that angle is not optimized on a patient-specific basis.